Chables frederick ryland



C. F. RYLAND.

MEANS FOR ILLUMINATING MAGNETIC COMPASSES. v

' APPLICATION FILED NOV. a0, 1918.

*Patented Mar. 9,1920.

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CHARLES FREDERICK RYLAND, 0F ALDERSHOT, ENGLAND.

MEANS FOR ILLUMINATING MAGNETIC COMPASSES.

Specification of Letters Patent.

Patented Mar. 9, 1920.

Application filed November 30, 1918. Serial No. 264,858.

To all whom it may concern:

Be it known that I, CHARLns FREDERICK RYLAND, a subject of the King of England,

residing at Aldershot, in the county of Hampshire, in the Kingdom of England, have invented new and useful Means for Illuminating Magnetic Compasses, of which the following is a specification.

This invention relates to prismatic compasses and like instruments of the kind fitted with an ordinary non-luminous dial.

Such instruments have previously been made and fitted with a dial having a transparent edge and with a spot of luminous compound fixed in the bottom of the case for the purpose of illuminating the degrees in the dark; but a luminous spot so placed would not be effective for illuminating an ordinary metal or other non-transparent dial.

My invention consists in applying an inverted holder carrying luminous compound. for the purpose of illuminating the scale of a non-transparent dial, for which purpose I dispose said holder with the compound over and above, or at the side of the'dial and between the prism and the dial, or, for use with a magnifying glass, on either side of the body of the compass or other instrument.

I prefer to adopt for the luminous compound a holder of curved shape fixed to the inside of the glass cover of the instrument so that a center space of the curve is left clear and transparent for the use of the prism or the magnifying glass. The results here attained are that the luminous com pound is made to throw its luminous rays only in a downward direction. This can be done in several other ways, but I prefer to make a shallow metal holder or receptacle of the desired shape and secure same, with the luminous side toward the dial, on the inside surface of the rotatory glass cover usually fitted to magnetic compasses and like instruments, so that the luminous rays will be thrown on to that part of the dial which is in the line. of sight of the prism or magnifying glass. If desired, the receptacle may be formed integrally with the frame of the rotatory glass cover or with the body of the instrument 1'. 6. inside the case under the glass cover or to the under-surface of the prism box.

In the accompanying drawings:

Figure 1 shows a prismatic compass with my invention applied thereto; Fig. 2 a surface view of same with the prism and hinged lid opened out to their fullest extent; Fig. 3 is a perspective view of the holder or receptacle for the luminous compound.

In these drawings A represents the receptacle for the luminous compound, B the dial of the instrument and C the prism.

In Figs. 1 and 2 the receptacle A is shown fitted in inverted position to the under side of the rotatory cover of the compass beneath the prism C. Another position of the receptacle is indicated at A in Fig. 1 where it is shown as applied to the side of the compass body beneath the prism G. As will be seen, in either position the light rays from the luminous compound fall upon that part of the upper face of the dial which is nearest to the prism and the receptacle is so shaped with a central opening and arranged as not to interfere with the sight line through the prism.

In the case of an instrument with a magnifying glass instead of a prism the luminous compound may be arranged at the diametrically opposite side of the instrument, 2'. e. at the part where the reading would be taken.

I claim:

In a prismatic compass, an inverted holder carrying luminous compound to direct light rays on to the upper face of the non-transparent dial of said compass and having a middle openin for observation of the dial and as describe CHARLES FREDERICK RYLAND. 

